The present invention relates to a large scale display device formed by an assembly of a number of image display tubes.
A conventional display device of this type, as shown in FIG. 1, includes image display tubes 1, block-shaped face plates 2 each having a number of image display tubes 1, and a frame 3 accommodating the face plates 2. A method of assembling the conventional display device will be described. For convenience in transportation, the image display section of the display device is divided into several blocks which are transported to a place where the display device is to be installed. In assembling these blocks, only the face plates are welded so that water will not enter the display device through the image display surface. The face plates are transported separately after the image display tubes and the control unit have been removed from the face plate. After the face plates have been assembled and welded, it is necessary to mount the image display tubes and the control units on the face plates again at the installation place. In order to improve the quality of a displayed image, the image display tube mounting pitch and arrangement are limited. Therefore, the configuration and dimensional errors of the junctions of adjacent block-shaped face plates are of great concern and accordingly the welding work at the installation place takes a great deal of labor and time.